This blog is dedicated to some basic information on the diagnosis and management of Lyme disease and other tick-related issues. Here is a hypothetical conversation between a patient and physician.
Patient: If I have a tick bite, what is my risk of developing Lyme disease?
Doctor: There are many variables that need to be addressed to answer this question. When I started working in a Lyme-endemic area over 10 years ago, the conventional wisdom was that a tick had to be on for 72 hours or more to transmit the Lyme bacteria. This seemed absurd. People now use a 24 hour cut off. Using any rigid period of time doesn’t make sense to me. The longer a tick is on, the higher the risk. If the tick is engorged with blood, one can assume the risk is higher. There is also variation from town to town and microclimate to microclimate in terms of the percentage of ticks that are infected with the Borrelia burgdorferi bacteria. A public health group found a range in our area between 10-20% but I’ve seen estimates at 30% or higher.
Patient: What is the best way to remove a tick?
Doctor: Consensus is to use a pair of tweezers and grasp as close to the skin and pull straight up. Most experts recommend avoiding matches and glop and other techniques that just piss of the tick causing him to dump the bacteria into your body out of spite.
Patient: I’ve heard that the tiny ticks are the deer ticks and are the ones that can transmit Lyme disease.
Doctor: For years, I would see someone in the office and they would say they pulled a tick off, but no worries, they could tell it wasn’t a deer tick. I was perplexed thinking there must be a high concentration of entomologists in my practice. One day, I realized they were all under the misconception that the tiny specks (the immature nymphs) were the deer ticks and the larger ticks were some other species. Each tick species has different life stages so a tiny tick and a corpulent adult can both transmit Lyme disease. The nymphs likely are responsible for more Lyme disease because they are harder to detect.
Patient: How is the diagnosis made of Lyme disease?
Doctor: There are several scenarios where a physician may make a diagnosis of Lyme disease. The simplest is a patient who presents with a classic bull’s eye rash. The next is someone who has a specific prolonged tick exposure and then within a week or so develops the classic symptoms of unexplained joint pains, fatigue, headaches and fevers. Not everyone presents the same, of course, but these are the most common symptoms. The third scenario, and the least common, is that someone has symptoms and the Lyme blood test is positive. Lyme disease is most often a diagnosis made on clinical grounds.
Patient: How long should someone be on antibiotics and which antibiotics are the most effective?
Doctor: This is a controversial area. There is wide variation in how practitioners handle this issue. A study done years ago showed that a person who was given 200mg of the antibiotic doxycycline within 48 hours of the exposure had a 90% lower risk of developing Lyme disease. This strategy is often used for someone with 12-24 hour exposure. Many Lyme experts are skeptical of this option. For someone with an engorged tick or an exposure over 24 hours there are several options: (1) no treatment and monitor for symptoms; (2) no treatment, monitor and do a Lyme blood test in a 2-4 weeks; (3) 200mg of doxycycline once; (4) 10 days of doxycycline [I remember one study years ago that said that a person diagnosed early with Lyme disease had cure with 10 days.]; (5) 3-4 weeks of doxycycline and this, of course, is the most aggressive strategy and used more often in patients exhibiting signs and symptoms of an early Lyme infection.
Patient: Which antibiotics are the best?
Doctor: Doxycycline has long been the antibiotic of choice. It can cause stomach upset and photosensitivity with potential for bad sunburns. Amoxicillin is the next option especially in kids under 10-12 years old because doxycycline can damage the teeth of younger children. Cefuroxime (or Ceftin) is also very effective.
Patient: What about chronic Lyme disease?
Doctor: This is a difficult area in terms of diagnosis and treatment. There is no simple answer on who should be treated and by whom with what antibiotic(s) and for how long with which adjunctive treatments. If chronic Lyme is under consideration, I would first try to find a regular physician that takes insurance who is knowledgeable on the issue. There are Lyme specialists in the mainstream, primarily infectious disease specialists, but in my experience, if the person has a negative Lyme blood test they will not consider chronic Lyme disease a possibility. Seeing an ID specialist is almost always a good idea however because many people with a wide variety of chronic health problems do not have chronic Lyme disease, so the ID specialist may identify some other underlying cause. There are alternative Lyme specialists in New England, New York and New Jersey, but they are typically private pay and working with them can incur significant cost. This puts chronically ill people in a difficult position. Reading Horowitz’s book Why Can’t I Get Better? would be one good resource in trying to sort things out.
Andrew Lenhardt, MD